Tire Compositions and Methods for Making Thereof

ABSTRACT

A tire composition is disclosed. The composition comprises a rubber component and based on 100 parts by weight (phr) of the rubber component, 50-200 phr of covered silica, with the covered silica comprising silica core and a first resin covering the silica core, wherein the first resin is not chemically bonded to the silica core. The silica core is covered with the first resin by mixing a slurry comprising silica core with a mixture containing the first resin as a solution, an aqueous dispersion; or a solution by dissolving the first resin in a solvent.

RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.16/948,601 with a filing date of Sep. 24, 2020, which is acontinuation-in-part of U.S. patent application Ser. No. 16/379,614 witha filing date of Apr. 9, 2019, which claims priority from U.S.Application No. 62/655,554, with a filing date of Apr. 10, 2018, thedisclosures are incorporated herein by reference.

FIELD

The disclosure relates to compositions for use in tire applications.

BACKGROUND

Treads of high-performance tires are expected to have outstandingtraction and handling properties, wet skid resistance, low rollingresistance, good winter performance and good wear characteristics. Theseproperties depend, to a great extent, on the dynamic visco-elasticityproperties of the rubber compositions used in making the tires andsuitable balance between these properties has to be found throughcareful design of the rubber composition of the tread.

To change the rubber composition visco-elastic properties, use of solidresins is well known. Despite the availability of liquid resins (whichhave demonstrated improvement of tire properties balance), solid resinsare being extensively used to change the rubber composition'svisco-elastic properties. Difficulties in handling liquid resins andcost associated with having to inject a liquid component into the rubbercomposition may be some of the reasons for non-use of liquid resins.

Rubber compositions have components such as a diene-based elastomer,which could be reinforced with a different type of filler such as carbonblack (CB) or precipitated silica. When silica is added to the rubbercomposition, it becomes difficult to disperse the silica inside theelastomer matrices. The difficulty in dispersing silica within theelastomer matrix arises because his hydrophilic surface (silica exhibitsstrong silica-silica interaction). To promote the silica-elastomerinteraction as well as to reduce the silica-silica interaction, it iswell known to those skilled in the art that a so-called silica couplingagent could be used. However, use of the silica coupling agent leads tosubstantial cost increase.

There is a need for improved methods for making rubber compositions formaking tires, and improved resin compositions enabling fine particlesilica to disperse uniformly throughout rubber compositions for makingtire treads.

SUMMARY

In one aspect, a tire composition is disclosed. The compositioncomprises a blend of a rubber component and based on 100 parts by weight(phr) of the rubber component; from 50 phr to 200 phr of covered silica,wherein the covered silica comprises silica core and a first resincovering the silica core. The first resin is selected from: a resinbeing liquid at room temperature, hard resin dispersions and emulsionsin water, and a hard resin in an organic solvent.

In embodiments, the resin-covered silica has an average primary particlesize of <1000 μm, and the resin-covered silica is formed in a processconsisting essentially of coating finely divided silica with acomposition consisting essentially of a first resin to coat at least asurface of the finely divided silica forming the resin-covered silica asseparate silica particles coated with the first resin.

In another aspect, a method to prepare a tire composition is disclosed.The method comprises mixing with a rubber component and based on 100parts by weight (phr) of the rubber component; from 50 phr to 200 phr ofcovered silica, wherein the covered silica comprises silica core and afirst resin covering the silica core.

In yet another aspect, a resin-coated silica composition is disclosed.The composition comprises a particulate material; and a resin selectedfrom a rosin-based resin, a terpene-based resin, a C5-C9 resin, ahydrogenated resin, a polymerization-modified rosin resin, a styrenatedterpene resin, a polyterpene resin, a phenolic terpene resin, anα-methyl styrene monomer resin, an α-methyl styrene phenolic resin, andcombinations thereof; wherein the resin is pre-coated onto a surface ofthe particulate material.

In embodiments, the resin-coated silica is formed by coating silicaparticulate with the resin. The resin is not chemically bonded to theparticulate material. The particulate material is selected from thegroup consisting of untreated silica, precipitated silica, crystallinesilica, colloidal silica, aluminum silicates, calcium silicates, fumedsilica, and mixtures thereof.

In embodiments, the resin is coated onto the surface of the silicaparticulate by providing a slurry mixture comprising the resin in any ofa solution, an aqueous dispersion, or a solution by dissolving the resinin a solvent; mixing the plurality of silica particulates with theslurry mixture for the resin to coat the surface of the silicaparticulates; and drying the mixture to recover the resin-coatedparticulate material.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph illustrating tangent delta vs. temperature performanceof the formulation of Examples 1, 3 and 7.

FIG. 2 is a graph illustrating loss modulus vs. temperature performanceof the formulation of Examples 1, 3 and 7.

FIG. 3 is a graph illustrating tangent delta vs. temperature performanceof the formulation of Examples 1, 2 and 5.

FIG. 4 is a graph illustrating loss modulus vs. temperature performanceof the formulation of Examples 1, 2 and 5.

FIG. 5 is a photograph of an embodiment of the Resin Covered Silica, asseparate minute particles.

DESCRIPTION

The following terms will be used throughout the specification and willhave the following meanings unless otherwise indicated.

“phr” means parts per hundred parts of elastomer (rubber).

“Elastomer” may be used interchangeably with the term “rubber,”referring to any polymer or combination of polymers consistent with ASTMD1566 definition.

“Polymer” and “interpolymer” are used interchangeably to mean higheroligomers having a number average molecular weight (Mn) equal to orgreater than 100, prepared by the polymerization or oligomerization ofat least two different monomers, including copolymers, terpolymers,tetrapolymers, etc.

M_(w) means the molecular weight average distribution calculatedaccording to:

$M_{w} = \frac{\Sigma_{i}N_{i}M_{i}^{2}}{\Sigma_{i}N_{i}M_{i}}$

where N_(i) is the number of molecules of molecular weight M_(i). Onemethod to calculate the M_(w) is determined using gel permeation/sizeexclusion chromatography (GPC-SEC) as described in ASTM D5296 (2005).

M_(n) is the number average of the molecular weights, calculatedaccording to:

$M_{n} = \frac{\Sigma_{i}N_{i}M_{i}}{\Sigma_{i}N_{i}}$

where N_(i) is the number of molecules of molecular weight M_(i). Onemethod to calculate M_(n) is determined using the GPC-SEC method in ASTMD5296 (2005).

M_(z) is a higher order molecular weight average, or the third powermolecular weight, calculated according to:

$M_{z} = \frac{\Sigma_{i}N_{i}M_{i}^{3}}{\Sigma_{i}N_{i}M_{i}^{2}}$

where N_(i) is the amount of substance of species i and M_(i) is themolecular weight of species i. One method to calculate M_(z) isdetermined using GPC-SEC method in ASTM D5296 (2005).

Polydispersity index (PDI) is calculated according to PDI=M_(w)/M_(n).

Tg (glass-liquid transition or glass transition) may be determinedaccording to ASTM D 6604 (2013).

T_(sp) (softening point) may be determined by ASTM E28, or a ring andball, or ring and cup softening point tests.

Tangent delta is expressed by a ratio of the measurement of energy lostas heat (loss modulus) versus the energy stored and released (storagemodulus). Tan delta and other relating viscoelastic properties can beobtained using a dynamic viscoelastic tester. Good wet traction ispredicted by a high value for G′ (loss modulus) and tan delta at 0° C.Low rolling resistance is predicted by low tangent delta values at 50°C. and higher temperatures. Tan delta at 100° C. can be used as anindicator of tire grip and other enhanced performance characteristicsunder extreme use conditions.

Hydroxyl value (OH—) is a measure of the content of free hydroxylgroups, expressed in units of the mass of potassium hydroxide (KOH) inmilligrams equivalent to the hydroxyl content of one gram of thechemical substance, determined per ASTM E222.

Properties such as tensile strength, elongation, and modulus can bemeasured following procedures described in ASTM D412.

Hardness refers to Hardness Shore A according to DIN 53506.

Mooney viscosity MS or ML (1+4) at 100° C. is according to DIN 53523.

Dynamic mechanical properties are measured via dynamic mechanicalanalysis (DMA) by a temperature-sweep in double shear mode from −60° C.to 100° C. with 1° C./min at 10 Hz and 0.1% (−60° C. till −5° C.) and 3%(−5° C. till 100° C.) dynamic strain using a Metravib+450N.

Tire Tread Wet Performance Predictive Properties are evaluated throughthe DMA by the Tan Delta at 0° C. (tan δ 0° C.) and higher value of theindex of wet grip performance, as obtained by Equation 5, are predictiveof better wet grip performance.

Index of wet grip performance=(tan δ 0° C. Comparative Example)/(tan δ0° C. of reference formulation)×100.

Tire Tread Rolling Resistance Predictive Properties are evaluatedthrough the DMA by the Tan Delta at 60° C. (tan δ 60° C.) and lowervalues of the index of fuel efficiency, as obtained by Equation 7, arepredictive of beneficial reduction in tire rolling resistance.

Index of fuel efficiency=(tan δ 60° C. of reference formulation)/(tan δ60° C. Comparative Example)×100.

Tire Tread Winter Predictive Performance is evaluated through the DMA bythe G′ at −20° C. (G′−20° C.) and lower values of the index of winterperformance, as obtained by Equation 8, are predictive of beneficialimprovement in tire winter performance.

Index of winter performance=(G′−20° C. of reference formulation)/(G′−20°C. Comparative Example)×100.

Tire Tread Dry Handling Performance is evaluated through the DMA by theG′ at 30° C. (G′30° C.) and lower values of the index of dry handling,as obtained by the following Equation 9, are predictive of beneficialimprovement in tire winter performance.

Index of dry handling=(G′30° C. Comparative Example)/(G′30° C. ofreference formulation)×100.

“Resin dispersion” refers to a mixture of a resin composition within afluid phase, e.g., an aqueous phase or organic fluid phase, for aslurry, an emulsion, or a solution.

Disclosed herein is a composition that can be used for a number ofapplications, including tires. The composition comprises a blend of therubber component and based on 100 parts by weight (phr) of the rubbercomponent and from 50 phr to 200 phr of a resin-covered silica.

Resin Covered Silica: The Resin Covered Silica has two components,namely a “Silica Core” and a “First Resin” covering the Silica Core. TheCovered Silica comprises from 1% to 70% of the First Resin, or from 3%to 50% of the First Resin, or from 5 to 30% of the First Resin, thepercentage being expressed in terms of total weight of the CoveredSilica.

Silica Core: The Silica Core can be formed of any type or particle sizesilica or another silicic acid derivative, or silicic acid, processed bysolution, pyrogenic, or the like methods, including untreated,precipitated silica, crystalline silica, colloidal silica, aluminum orcalcium silicates, fumed silica, and the like. Precipitated silica canbe conventional silica, semi-highly dispersible silica, or highlydispersible silica. Further examples include silica having a BET surfacearea, as measured using nitrogen gas, from 40 to 600 m²/g, or 50 to 250m²/g, or 90 to 215 m²/g. In one embodiment, the silica is characterizedby having a dibutylphthalate (DBP) absorption value in a range of 100 to400.

In embodiments, the silica has an average primary particle size asdetermined by the electron microscope in the range of 0.01 to 2000micron. In embodiments, the silica has an average primary particle sizeof <1500 μm, <1000 μm, <100 μm, or <80 μm, or <50 μm, or >30 μm, or from50-10,000 nm, or 5-1000 nm, or less than 10 nm. The primary particlesize refers to the size of each of the minute separate particlesthemselves.

Various commercially available amorphous synthetic precipitated silicas(precipitated silicas) can be used as Silica Core. Such silicas may becharacterized, for example, by their BET and CTAB surface areas. CTABspecific surface area (measured in accordance with ASTM d D3765 d 80) ofthe silica ranges from 100 to 300 m²/g. In an embodiment, CTAB specificsurface area (measured in accordance with ASTM d D3765 d 80) of thesilica ranges from 60 to 200 m²/g, or 120 to 250 m²/g. Representative ofsuch silicas, for example only and without limitation, are silicas fromPPG Industries under the Hi-Sil trademark with designations 210, 243,etc.; silicas from Rhodia, with designations of Zeosil 1 165MP andZeosil 165GR, silicas from Evonic with designations VN2 andVN3, andsilicas from Huber such as Zeopol 8745 and Zeopol 8715.

In embodiments, the Silica Core comprise amorphous silica having a losson drying of up to about 9%, a pH of about 5 to 10 about 9, an ignitionloss of about 6% to about 12%, a soluble salt content of up to about 2%,and a BET or CTAB specific surface area of about 50 to about 250 m²/g.

It should be noted that in addition to silica or in place of silica foruse as Silica Core, other materials can also be used and coated withresins, e.g., carbon black.

The First Resin: The First Resin can be any of a terpene-based resin, ahydrocarbon-based resin, a rosin-based resin and combinations thereof.For use in coating the Silica, the First Resin can be in a form of ahard resin dissolved in an organic solvent, a liquid resin (at roomtemperature), or a resin dispersion and/or emulsion.

In one embodiment, the First Resin is a terpene resin which comprisesα-pinene, β-pinene, δ-3 carene, limonene, dipentene, β-phellandrene andpyrolysates of α-pinene, β-pinene, δ-3 carene, δ-2 carene, turpentine,dipentene, limonene, and combinations thereof. Other examples of terpeneresins include polyterpene resins and terpene phenol resins. Thepolyterpene resin is a resin obtained by polymerizing a terpenecompound, or a hydrogenated product of the resin. Examples of terpenephenol resins include resins prepared by cationic polymerization of theterpene compound, a phenol compound, and condensation reactions withformalin. Examples of the phenol compound include phenol, bisphenol A,cresol, and Xylenol.

In another embodiment, the First Resin is an aromatic petroleum resin,for example, resins obtained by polymerizing a C8 to C10 aromaticfraction which is generally obtained by naphtha cracking and whichincludes, as a main monomer, vinyltoluene, indene, or methylindene.Other aromatic fractions include styrene analogues such asα-methylstyrene or β-methylstyrene and styrene. The aromatic petroleumresin may contain a coumarone unit. The aromatic petroleum resin mayalso contain an aliphatic olefin unit, a phenol unit, or a cresol unit.Examples of the aromatic petroleum resins include coumarone-indeneresins, indene resins, aromatic vinyl polymers (resins obtained bypolymerizing α-methylstyrene and/or styrene), and C9 hydrocarbon resins.Other examples include substituted or unsubstituted units derived fromcyclopentadiene homopolymer or copolymer resins,dicyclopentadienehomopolymer or copolymer resins, C5 fractionhomopolymer or copolymer resins, C9 fraction homopolymer or copolymerresins, alpha-methylstyrene homopolymer or copolymer resins, andcombinations thereof.

In yet another embodiment, the First Resin is a rosin-based resin,selected from a rosin ester-based resin, a rosin oligoester based resin,and combinations thereof.

In one embodiment of a hard resin, the First Resin comprises hydrocarbonresin based on monomers such as derived from C5, C5/C9, DCPD, terpenes,eventually aromatically modified with alpha-methyl styrene, vinyltoluene, vinyl mesitylene, tertiary butyl styrene. Examples ofcommercially available hard resins include SYLVATRAXX 4202, 5216, 4401,6720, Oppera PR373, 383 and 393, Escorez 5340, Escorez 5637, QuintoneA100, Polyster T160, SYLVARES RE100L, SYLVATAC RE95.

In one embodiment of a soft resin (liquid resin), the First Resin has asoftening point in the range of −20 to 45° C.; or 0° C. and 25° C.; orbetween 10° C. and 25° C. Based on the fact that the soft resin is veryclose to the softening point at room temperature (23° C.), it is eitheralready liquid or very soft at room temperature. A soft resin may be anatural resin or synthetic resin. Examples of soft resins include mediumto higher-molecular weight compounds from the classes of paraffinresins, hydrocarbon resins, polyolefins, polyesters, polyethers,polyacrylates or amino resins.

In embodiments, the First Resin is a liquid aromatic petroleum resinhaving a softening point within the above range, e.g., liquidcoumarone-indene resins, liquid terpene resins, and liquid rosin resins.Examples of suitable soft resin include, for example, polyterpene resinssold commercially as Sylvares TR A25 from Kraton Chemical.

In other embodiments, the First Resin is an aliphatic C5-C9 hydrocarbonresin. Examples include aliphatic C5 hydrocarbon resins, e.g., resinscommercially marketed under the Wingtack name. Other examples of softresins include hydrocarbon resins, for example, Picco A10 and RegaliteR1010. Further examples of suitable soft resins include Escorez™ 5040from ExxonMobil Chemical.

In embodiments, the First Resin comprises a rosin resin, e.g., gumrosin, wood rosin, tall oil rosin, or dismutation products obtained bydismutation of the rosin material, stabilized rosins obtained byhydrogenating rosins, and polymerized rosins; esterified rosins (rosinester resins), phenol-modified rosins, unsaturated acid (e.g., maleicacid)-modified rosins and formylated rosins obtained by reducing rosins.Examples include rosin esters and tall resin esters, commerciallyavailable as Sylvatac RE12, RE10, RE 15, RE20, RE25 or RE40 from KratonChemical.

In embodiments, the First Resin comprises a resin in an aqueousdispersion with a solids content of from 35% to 80%. An example is arosin resin in an aqueous dispersion, e.g., AQUATAC 6025 from KratonChemical with a softening point of 26° C. and a solid content of 59-63wt. %. Yet another example is an aqueous dispersion with 50% rosin acidsin aqueous solution (SNOWTACK 765A from Lawter), or 55% rosin esters indispersion (SNOWTACK SE780G from Lawter). Other examples includealiphatic hydrocarbon resin in an aqueous, solvent free, dispersion suchas TACOLYN 5002 from Eastman Chemical with a softening point of 70-130°C. and a solid content of 45-50%.

In embodiments, the First Resin has a Mw ranging from 400 g/mol to 2000g/mol; or from 500 g/mol to 1500 g/mol. In embodiments, the First Resinhas a Mz ranging from 1300 g/mol to 3500 g/mol.

In embodiments, the First Resin is characterized as having a meltviscosity at 177° C. of 50 to 15000 mPa·s; or greater than 100 mPa·s; orless than 14500 mPa·s. Melt viscosity is measured under the conditionsof the number of revolutions of 3 rpm and a temperature of 177° C. witha Brookfield RTV viscometer. In embodiments, the First Resin ischaracterized as having a Tsp in the range of from 80° C. to 170° C., orfrom 100° C. to 160° C., or from 125° C. to 155° C.

In embodiments, the First Resin has a Tg from −40° C. to +120° C., orfrom −35° C. to 100° C.

In embodiments, the First Resin is characterized by a hydroxyl numberranging from 0 mg KOH/g to 30 mg KOH/g, or from 2 mg KOH/g to 20 mgKOH/g, or from 4 mg KOH/g to 15 mg KOH/g.

In embodiments, the First Resin is characterized as having apolydispersity index (PDI) of from 1.25 to 2.5, or from 1.3 to 2.0, orfrom 1.32 to 1.8.

In embodiments, the First Resin has a softening point of 60° C. or more;a glass transition temperature from −30° C. to 100° C.; a BrookfieldViscosity (ASTM D-3236) of 50 to 25,000 mPa·s at 177° C.

Method for Preparing Resin Covered Silica: In embodiments, the FirstResin is present in a form of resin dispersion for the pre-coating ofthe Silica Core (finely divided silica), forming Resin Covered Silica.

In embodiments, the resin dispersion can be prepared by emulsifying theresin in the fluid phase at temperature above the resin's melting point,and then cooling to provide finely dispersed solid resin particulateswithin the fluid phase. In embodiments, the resin is liquid or liquefiedfor a sprayable solution, e.g., by dissolving the resin in an organicliquid or dispersing the resin in water.

In embodiments where the First Resin is a hard resin, the First Resin isdissolved in a solvent in a concentration ranging between 5 to 90% at anelevated temperature to form a melt. The melt is then dispersed inliquid phase. Water is an example of a dispersion medium, but variousother solvents may be used. Examples of solvent for use in dissolvingthe First Resin include but are not limited to toluene, ethylacetate,methylethylketone, hexane.

The Resin Covered Silica in one embodiment is prepared by first forminga slurry of Silica Core. By way of a non-limiting example, finelydivided silica core is mixed with a liquid medium such as water oralcohol to obtain a silica slurry. In the next step, the silica surfaceis treated or coated by mixing with the First Resin as a resindispersion, forming a mixture.

In another embodiment, the Resin Covered Silica is prepared by mixingfinely divided silica (dry form) into a resin dispersion, forming amixture. The finely divided silica are immersed in the resin dispersionfor the resin to coat at least a surface of the finely divided silica,preferably the entire surface.

In yet another embodiment, the resin dispersion is sprayed onto thefinely divided silica, e.g., in a mixing tank equipped with sprayer, foruniform coating of the finely divided silica with the resin dispersion,forming Resin Covered Silica.

In embodiments after coating the silica with the resin, the resincoating layer formed on the divided silica particles can be subsequentlydried (e.g., air dried, or using pressurized air).

In yet other embodiments, after coating with the First Resin, the ResinCovered Silica can undergo a second coating, e.g., with the same resinor a resin different from the First Resin, or a composition differentfrom a First Resin, e.g., a silane. In yet other embodiments, the finelydivided silica is first coated with composition different from the FirstResin, e.g., a functional silane before being coated with the FirstResin. It is noted that the average primary particle size of the finalResin Covered Silica remains essentially the same as the starting finelydivided silica particles, e.g., having an increase in average primaryparticle size of <10%, <5%, <3%, and <2% after each coating.

In embodiments where a soft resin is used as a First Resin, it isoptional to add a solvent prior to mixing the First Resin with theslurry of Silica Core.

The concentration of Silica Core in the resin dispersion (slurry) can bevaried. In embodiments, silica slurries can contain 0.1% to 75% byweight silica based on the weight of the slurry. In some embodiments,the silica concentration ranges from 10 to 20 wt. %, or 0.1-75 wt. %, or1-20 wt. %, or 5-50 wt. %, or 10-35 wt. %, or 10-25 wt. %.

The concentration of the First Resin in the mixture of slurry and FirstResin for coating the Silica Core can also vary within relatively widelimits, e.g., any of 1 to 75 wt. %; 5 to 40 wt. %; and over 10 wt. %.

In the process based on the First Resin used for coating, thetemperature of the mixture is suitably maintained to for the First Resinto uniformly coat the Silica Core, and for the removal of the liquidmedium from the mixture, based on the nature of the liquid medium usedin forming the slurry, and can be varied within relatively wide limits.

After the coating and drying steps, the First Resin is not chemicallybonded to the Silica Core. The Resin Covered Silica remains in the formof minute separate particles as shown in FIG. 5. The particle size ofResin Covered Silica remains essentially unchanged, with an averageprimary particle size within 10% of the average primary particle size ofthe starting Silica Core (prior to being coated or covered with theFirst Resin). In embodiments, the average primary particle size of theResin Covered Silica particle size has just a slight increase, of lessthan 10% compared to the average primary particle size of the starting(uncoated) silica particles, or an increase of less than 5%, or anincrease of less than 3%, or an increase of less than 2%, or essentiallythe same as the starting Silica Core.

It is also observed that the surface area of the Resin Covered Silica(coated silica particulates) remains essentially the same as the surfacearea of the starting Silica Core (uncoated silica particulates).

In embodiments, the Resin Covered Silica in the form of minute separateparticles has an average primary particle size of <100 μm, or <80 μm, or<50 μm, or >30 μm, or from 50-10,000 nm, or 5-1000 nm, or less than 20μm; with BET surface area of 5-500 m²/g, or 10-300 m²/g, or less than250 m²/g, or at least 50 m²/g. The primary particle size refers to thesize of each of the minute separate particles themselves.

Rubber Component: The term “rubber” or “elastomer” include both naturalrubber and its various raw and reclaim forms, as well as varioussynthetic rubbers.

In embodiments, the rubber component comprises any of unsaturated dieneelastomer selected from polybutadienes, natural rubber, syntheticpolyisoprenes, butadiene copolymers, isoprene copolymers and themixtures of such elastomer. In one embodiment, the rubber is selectedfrom butyl rubber, halogenated butyl rubber, and EPDM (EthylenePropylene Diene Monomer rubber), and mixtures thereof. In anotherembodiment, the rubber component is selected from natural rubber (NR),styrene-butadiene rubber (SBR), butadiene rubber (BR), syntheticpolyisoprene rubber, epoxylated natural rubber, polybutadiene rubber,nitrile-hydrogenated butadiene rubber HNBR, hydrogenated SBR, ethylenepropylene diene monomer rubber, ethylene propylene rubber, maleicacid-modified ethylene propylene rubber, butyl rubber,isobutylene-aromatic vinyl or dienemonomer copolymers, brominated-NR,chlorinated-NR, brominated isobutylene p-methylstyrene copolymer,chloroprene rubber, epichlorohydrinhomopolymers rubber,epichlorohydrin-ethylene oxide or allylglycidyl ether copolymer rubbers,epichlorohydrin-ethylene oxide-allylglycidyl ether terpolymer rubbers,chlorosulfonated polyethylene, chlorinated polyethylene, maleicacid-modified chlorinated polyethylene, methylvinyl silicone rubber,dimethyl silicone rubber, methylphenylvinyl silicone rubber, polysulfiderubber, vinylidene fluoride rubbers, tetrafluoroethylene-propylenerubbers, fluorinated silicone rubbers, fluorinated phosphagen rubbers,styrene elastomers, thermoplastic olefin elastomers, polyesterelastomers, urethane elastomers, and polyamide elastomers.

Examples of SBR rubber include an emulsion-polymerized styrene-butadienerubber (un-modified E-SBR), a solution-polymerized styrene-butadienerubber (un-modified S-SBR) and modified SBRs obtained by modifyingterminals thereof (modified E-SBR and modified S-SBR) can be used. Inone embodiment, the rubber component comprises rubber components otherthan the SBR and the BR such as a natural rubber (NR), an isoprenerubber (IR), an epoxidized natural rubber (ENR), a butyl rubber, anacrylonitrile butadiene rubber (NBR), an ethylene propylene diene rubber(EPDM), a chloroprene rubber (CR) a styrene-isoprene-butadiene rubber(SIBR), used alone or in combinations as needed.

The rubber component may be coupled, star-branched, branched, and/orfunctionalized with a coupling and/or star-branching orfunctionalization agent. The branched rubber can be any of branched(“star-branched”) butyl rubber, halogenated star-branched butyl rubber,poly(isobutylene-co-p-methylstyrene), brominated butyl rubber,chlorinated butyl rubber, star-branched polyisobutylene rubber, andmixtures thereof.

In embodiments, the rubber is end-group functionalized to improve itsaffinity for fillers, such as carbon black and/or silica. In oneembodiment, the functionalized rubber made by living polymerizationtechniques is compounded with sulfur, accelerators, antidegradants, afiller, such as carbon black, silica or starch, and other suitablechemicals. Examples of coupling and/or star-branching orfunctionalizations include coupling with carbon black as a filler, e.g.,with functional groups comprising a C—Sn bond or of aminated functionalgroups, such as benzophenone; coupling with a reinforcing filler, suchas silica, e.g., silanol functional groups or polysiloxane functionalgroups having a silanol end; alkoxysilane groups, polyether groups.

In embodiments, the rubber component is a highly unsaturated rubber,end-chain functionalized with a silanol group. In embodiments, therubber component is a functionalized diene rubber bearing at least onSiOR function, R being a hydrogen or a hydrocarbon radical. In yetanother embodiment, the rubber component consists of SBR, or of SBR andBR for improved wet grip performance. In other embodiments, the rubberis epoxide-functionalized (or epoxidized), bearing epoxide functionalgroups. The epoxidized elastomer can be selected from the groupconsisting of epoxidized diene elastomers, epoxidized olefinicelastomers, and mixtures thereof.

Cross-Linking Agents: In one embodiment and depending on the rubbercomponent used, the rubber component in the composition may becross-linked by adding curative agents, for example sulfur, metals,metal oxides such as zinc oxide, peroxides, organometallic compounds,radical initiators, fatty acids, and other agents common in the art.Zinc oxide, typically at 5 phr, is added to form zinc halide that thenacts as the catalyst for the vulcanization of the rubber compounds.Other known methods of curing that may be used include, peroxide curesystems, resin cure systems, and heat or radiation-induced crosslinkingof polymers. Accelerators, activators, and retarders may also be used inthe curing process.

The cross-linking agent content is preferably between 0.3 and 10 phr inone embodiment, or between 0.5 and 5.0 phr, or at least 0.5 phr in therubber composition.

Second Resin: The composition may additionally comprise a Second Resin,which can be the same or different than the First Resin, and which ispresent in an amount less than the typical amount of resin required forthe rubber composition to have the desired properties and performance.As with the First Resin, the Second Resin can be any of a terpene-basedresin, a hydrocarbon-based resin, a rosin-based resin and combinationsthereof.

The Second Resin herein includes substituted or unsubstituted unitsderived from cyclopentadiene homopolymer or copolymer resins (referredto as CPD), dicyclopentadiene homopolymer or copolymer resins (referredto as DCPD or (D)CPD), terpene homopolymer or copolymer resins, rosinderived resins, rosin/rosin esters, pinene homopolymer or copolymerresins, C5 fraction homopolymer or copolymer resins, C9 fractionhomopolymer or copolymer resins, alpha-methylstyrenehomopolymer orcopolymer resins, and combinations thereof. In one embodiment, theSecond Resin may further include units derived from (D)CPD/vinylaromaticcopolymer resins, (D)CPD/terpene copolymer resins, terpene/phenolcopolymer resins, (D)CPD/pinene copolymer resins, pinene/phenolcopolymer resins, (D)CPD/C5 fraction copolymer resins, (D)CPD/C9fraction copolymer resins, terpene/vinylaromatic copolymer resins,terpene/phenol copolymer resins, pinene/vinylaromatic copolymer resins,pinene/phenol resins, C5 fraction/vinylaromatic copolymer resins, andcombinations thereof.

In embodiments, the Second Resin is a terpene-based resin, e.g., aterpene phenol resin. In another embodiment, the Second Resin is aterpolymer derived from A) at least one monomer selected from the groupconsisting of terpenes and mono- and bi-cyclic mono- and bi-unsaturatedhydrocarbons; B) at least one monomer selected from the group consistingof vinyl aromatic compounds and component; and C) at least one monomerselected from the group consisting of phenolic compounds. Examples ofvinyl aromatic compounds include styrene and alkyl substituted styrenesuch as α-methyl styrene (“AMS”). In yet another embodiment, the SecondResin is a rosin/rosin ester-derived resin.

The Second Resin can be used in an amount from 3 to 100 phr; or from 5to 70 phr; or from 8 to 30 phr, or less than 20 phr, used in an amountless than would be required if Resin Coated Silica was not present inthe tire composition. In embodiment, the rubber composition includes anyof 5, 10, 15, 20, 25, 30, 35, 40, or in any range from to or between anytwo of the foregoing numbers of the Second Resin.

Fillers: In one embodiment, the tire composition further includesfillers (other than Resin Coated Silica) in an amount from 50 to 200phr. The term “filler” refers to any material that is used to reinforceor modify physical properties, impart certain processing properties, orreduce the cost of an elastomeric composition. Examples of fillersinclude, but are not limited to, calcium carbonate, carbon nanotube,clay, (uncoated) silica, mica, talc, titanium dioxide, alumina, zincoxide, starch, wood flour, carbon black, or mixtures thereof. Otherfillers may be used include, but are not limited to, particulate fillersincluding ultra-high molecular weight polyethylene (UHMWPE), particulatepolymer gels, and plasticized starch composite fillers known in the art.The fillers may be any size and typically range from 0.0001 μm-100 μm.

Optional Plasticizer Component: “Plasticizer” (also referred to as aprocessing oil), refers to a petroleum-derived processing oil andsynthetic plasticizer to extend elastomers and improve theprocessability of the composition. The amount of plasticizer is presentin an amount of 0-35 phr, or 5 to 25 phr, or less than 20 phr. In someembodiments, plasticizer is present in an amount of weight ratio ofresin to plasticizer of >1, or >3, or >6. Examples of plasticizersinclude aliphatic acid esters, hydrocarbon processing oils, tall oilpitch and modified tall oil pitch, and combinations thereof.

In embodiments, the plasticizer is a modified tall oil pitch selectedfrom the group of a pitch ester, a decarboxylated tall oil pitch, a soapof tall oil pitch, a thermally treated tall oil pitch, and a thermallyand catalytically treated tall oil pitch.

In embodiments, the plasticizer includes both extending oil present inthe elastomers, and process oil added during compounding. Examplesinclude aromatic, paraffinic, naphthenic, and low PCA oils, such as MES,TDAE, and heavy naphthenic oils, and vegetable oils such as sunflower,soybean, and safflower oils. Examples of low PCA oils include thosehaving a polycyclic aromatic content of <3 wt. %. Suitable vegetableoils include, for example, soybean oil, sunflower oil and canola oilwhich are in the form of esters containing a certain degree ofunsaturation.

Other Additives: The composition can be compounded with other componentsknown in the art in amounts of up to 50 phr, or up to 30 phr, or up to20 phr, such as sulfur donors, curing aids, such as accelerators,activators and retarders and processing additives, pigments, fatty acid,zinc oxide, waxes, antioxidants and antiozonants and peptizing agents.

Methods for Forming: The rubber composition can be formed by methodsknown to those having skill in the rubber mixing art. For example, thecomponents are typically mixed in two or two stages, for example, atleast one non-productive stage followed by a productive mix stage. Thefinal curatives, e.g., sulfur-vulcanizing agents are typically mixed inthe final stage which is conventionally called the “productive” mixstage in which the mixing typically occurs at a temperature, or ultimatetemperature, lower than the mix temperature(s) than the precedingnon-productive mix stage(s).

The Resin Coated Silica can be added in any stage, e.g., during at leastone of the non-productive stage and productive mix stage. In anembodiment, the Resin Coated Silica can be added during thenon-productive stage.

In a tire composition, the tire composition comprises from 20 phr to 150phr of the Resin Covered Silica, or from 30 phr to 100 phr Resin CoveredSilica, or from 50 phr to 75 Resin Covered Silica, or at least 10 phrResin Covered Silica, or at least 20 phr Resin Covered Silica, or lessthan 200 phr.

The rubber composition may be subjected to a thermomechanical mixingstep. The thermomechanical mixing step generally comprises a mechanicalworking in a mixer or extruder for a period of time suitable in order toproduce a rubber temperature between 140° C. and 190° C. The appropriateduration of the thermomechanical working varies as a function of theoperating conditions, and the volume and nature of the components. Forexample, the thermomechanical working may be from 1 to 20 minutes.

Industrial Applicability: Besides tire applications, the composition canbe extruded, compression molded, blow molded, injection molded, andlaminated into various shaped articles including fibers, films,laminates, layers, industrial parts such as automotive parts, appliancehousings, consumer products, packaging, and the like.

In tire applications, the composition is useful for a variety of tiressuch as truck tires, bus tires, automobile tires, motorcycle tires,off-road tires, aircraft tires, and the like. The compositions may alsobe fabricated into a component of a tire, e.g., treads, sidewalls,chafer strips, tire gum layers, reinforcing cord coating materials,cushion layers, and the like.

The composition can also be useful in a variety of applications,including tire curing bladders, inner tubes, air sleeves, hoses, beltssuch as conveyor belts or automotive belts, solid tires, footwearcomponents, rollers for graphic arts applications, vibration isolationdevices, pharmaceutical devices, adhesives, caulks, sealants, glazingcompounds, protective coatings, air cushions, pneumatic springs, airbellows, accumulator bags, and various bladders for fluid retention andcuring processes. They are also useful as plasticizers in rubberformulations; as components to compositions that are manufactured intostretch-wrap films; as dispersants for lubricants; and in potting andelectrical cable filling and cable housing materials.

The composition may also be useful in molded rubber parts such asautomobile suspension bumpers, auto exhaust hangers, and body mounts. Inyet other applications, compositions can also be useful in medicalapplications such as pharmaceutical stoppers and closures and coatingsfor medical devices.

It should be noted that the Resin Covered Silica can be used inapplications other than tires, and in amounts depending on theapplications and the matrix material, e.g., filler material such asanti-skid material for high-friction surface treatment, glass beads forroad marking applications, rubber, etc. In embodiments, theconcentration of the Resin Covered Silica with respect to the matrixmaterial ranges from 0.1 to 50 wt. %, or 0.1-5 wt. %, or 1-10 wt. %, or5-20 wt. %, or 15-30 wt. %, or 25-50 wt. %.

Properties: Not wishing to be bound by theory, it is believed that withthe use of the Resin Covered Silica, the resin is not chemically bondedto the silica core, allowing the resin to be released into thecomposition during mixing, thereby delivering the desired changes inviscoelastic properties to achieve improved performance. Further, theresin coating reduces the hydrophilic character of the silicaconglomerates. With the elastomer matrices having a hydrophobiccharacter, the resin coating improves the incorporation of the silicacoated with resin component into the elastomer matrices when comparedwith its equivalent virgin silica. Additionally, the use of resin coatedsilica enables the composition to be substantially free of silicacoupling agent, further reduce costs.

Further, pre-formed Resin Covered Silica helps avoid issues related tohandling polymer resins, which are sticky, tacky substances. In thetraditionally practiced method of compounding all of the separateingredients in a mixing device, one has to deal with the difficult taskof handling the sticky and tacky resins. A pre-formed Resin CoveredSilica allows for more uniform dispersion of both the silica and resinas particles throughout the rubber composition used in making tiretreads. Lastly, pre-formed Resin Covered Silica helps obviate the strongsilica-silica interaction, which can occur when silica and resin aremixed together as separate individual components. The pre-forming avoidsthe agglomeration of the silica particles, and in turn promotes bettersilica-elastomer interaction in the compounding step.

In tire applications, the use of Resin Covered Silica has showed toenhance the performance of a tire. In embodiments, tire compositionsshow significant reduction in rolling resistance and improvement in wetgrip performance, as compared to compositions with equal amounts ofsilica and the resin as separate components.

With respect to reduction in rolling resistance, tire compositions withthe Resin Covered Silica in embodiments show a tan δ at 60° C. that isat least at least 3% less, or at least 5% less, or at least 8% less thanthe tan δ at 60° C. of a composition with equal amounts of silica andthe resin as separate components.

With respect to improved wet traction (wet grip properties), the tirecomposition shows at least 5% improvement in tan δ at 0° C., or at least10%, or at least 15%, or at least 25% improvement over the tan δ at 0°C. of a tire composition with equal amounts of silica and the resin asseparate components.

With respect to DIN abrasion assistance, in embodiments, tirecompositions with the Resin Covered Silica has a DIN abrasion valueimprovement of at least 5%, or at least 10%, or at least 15%, over theDIN abrasion value of a comparable composition containing equal amountsof silica and the resin as separate components.

In embodiments, the composition has a DIN abrasion relative volume lossof less than 150 mm³, or less than 125 mm³, or less 100 mm³, or from 60to 120 mm³.

In embodiments, the tire rubber composition has a tan δ at 60° C. of0.20 or less, or between 0.08 to 0.20, or less than 0.18, or less than0.16, or less than 0.14, or less than 0.10.

In embodiments, the tire rubber compositions have a tan δ at 0° C. of atleast 0.50, or at least 0.57, or between 0.58 to 0.65, or at least 0.60.

Examples: The following examples are intended to be non-limiting.

Different compositions having formulations shown in Table 1 areprepared. Chemicals other than sulfur and a vulcanization acceleratorwere kneaded with a 0.2 L enclosed mixer at the temperature at thedischarge of 150° C. for 5.5 minutes to obtain a kneaded product. Thenthe kneaded product was re-milled for 4 minutes up to a temperature of145° C. Then, the kneaded product, sulfur and the vulcanizationaccelerator, were mixed using the same mixer for 2 minutes until thetemperature reached 100° C. to obtain an unvulcanized rubbercomposition. The obtained unvulcanized rubber composition was formed.Rubber sample preparation for testing was done according to ISO23529:2010

Resin A is a rosin ester based resin from with a Tg of −23° C. and anacid value of 60-80. Resin B is a polyterpene based resin with a Tg of−19° C. Both are commercially available from Kraton Chemical. SCR-20A isprecipitated silica covered with 20% in virgin silica weight of resin A.SCR-20-B is precipitated silica covered with 20% in virgin silica weightof resin B. The precipitated silica is of the type commonly used in tireformulations.

TABLE 1 Formulations (in phr) and performance properties ComparativeExamples Examples 1 4 7 2 3 5 6 SBR1 48 48 48 48 48 48 48 BR 30 30 30 3030 30 30 SBR2 35 35 35 35 35 35 35 Silica 80 80 80 SCR-20A 80 96 SCR-20B80 96 Resin A 16 Resin B 16 Carbon Black 5 5 5 5 5 5 5 Silane 8 8 8 8 88 8 Zinc Oxide 3 3 3 3 3 3 3 Stearic acid 2 2 2 2 2 2 2 Anti ageingagents 3.5 1 1 1 1 1 1 Wax 1 1 1 1 1 1 1 Oil 20 4 4 20 4 20 4 CBS 1.91.9 1.9 1.9 1.9 1.9 1.9 DPG 2.5 2.5 2.5 2.5 2.5 2.5 2.5 Sulfur 2.3 2.32.3 2.3 2.3 2.3 2.3 Evaluation Index of wet grip 100 111 118 98 119 92114 performance Index of Dry grip 100 106 141 100 139 79 109 Index offuel efficiency 100 94 69 95 72 120 92 Index of winter performance 10084 57 149 56 208 78 Index of dry handling 100 94 129 65 132 49 97 * CBS= N-cyclohexyl-2-benzothiazolesulfenamide * DPG = 1,3-diphenylguanidine

The comparative examples use a virgin silica in combination with eitheroil (1), or with one the resin A or B replacing the oil. Both resinsshow an improvement in the wet grip performance indicators. The rosinester resin (7) gives more improvement than the polyterpene (4) in termof wet grip, dry grip and dry handling indicator. The polyterpene willnevertheless give a better balance of wet grip/rolling resistancebalance.

When the covered silica is used, comparing (4) and (6) or (7) with (3),where the virgin silica level and resin level were kept the same, showscomparable effect. This show that silanisation is taking place, and thatthe resin which was initially covering the silica surface does notappear to have any detrimental effect.

By replacing the virgin silica part by part by the covered silica, thetotal amount of silica in the formulation (2) and (5) is reduced.Reducing the quantity of silica should reduce the wet grip indicator andimprove the rolling resistance and the winter performance as it could beobserved when comparing (1) (5). But when comparing (1) and (2), theresults show that the dry grip and wet grip indicators are maintainedand the winter performance greatly improves.

Liquid rosin ester can be used in tire rubber compositions to improvewet grip indicator, dry grip indicator, and handling indicator. The useof resin coated silica gives the same results as if resin and silicawere mixed separately, demonstrating that these resins do not influencethe silanisation. As shown for use in tire treads, the use of a resincoated silica gives the same final compound properties as if the twocomponents (silica and resin) are mixed separately. In another example,it is shown that the winter performance can be improved withoutcompromising the wet grip performance. In another example, the use isshown to improve the wet grip indicator and the dry grip indicator. Inanother, use of resin coated silica is shown to improve the wet gripindicator with limited effect on the rolling resistance indicator.

The results are also illustrated with the Figures, including: FIG. 1, agraph illustrating tangent delta vs. temperature performance of theformulation of Examples 1, 3 and 7; FIG. 1, a graph illustrating lossmodulus vs. temperature performance of the formulation of Examples 1, 3and 7; FIG. 3, a graph illustrating tangent delta vs. temperatureperformance of the formulation of Examples 1, 2 and 5; and FIG. 4, agraph illustrating loss modulus vs. temperature performance of theformulation of Examples 1, 2 and 5.

Example 7: This example is for a production run with large mixingequipment (˜400 L Banbury, which does not mix as well as with lab scaleequipment of 1.5 L Banbury), a rubber composition containing pre-formedresin covered silica showed a dramatic increase in performance. Table 2shows results with a 10% increase in dry traction tests (tan delta @ 30°C.) and a 20% increase in wet traction test (tan delta @ 0° C.) over arubber composition with resin and silica as separate components andcombined together in-situ

TABLE 2 Test Track Performance Control Tires Experimental TiresParameters Lab Indicator (Indexed) (Indexed) Dry Traction Tan Delta @100 110 (Higher is Better) 30 C. Wet Traction Tan Delta @ 100 120(Higher is Better) 0 C.

Embodiments herein include:

1. A composition comprising: a particulate material; and a resincomposition comprising a rosin-based resin, a terpene-based resin, aC5-C9 resin, a hydrogenated resin, a polymerization-modified rosinresin, a styrenated terpene resin, a polyterpene resin, a phenolicterpene resin, a resin dispersion, an α-methyl styrene monomer resin, anα-methyl styrene phenolic resin, or any combination thereof pre-coatedonto a surface of the particulate material.

2. The composition of claim 1, wherein the particulate materialcomprises silica particulates.

3. The composition of claim 2, wherein the resin composition comprises arosin-based resin, a terpene-based resin, or any combination thereof.

4. The composition of claim 3, wherein the resin composition comprises arosin ester resin, a liquid polyterpene resin, or any combinationthereof.

5. The composition of claim 3, wherein the resin composition comprises arosin ester resin, a liquid polyterpene resin, or any combinationthereof.

6. The composition of claim 2, wherein the silica particulates compriseprecipitated silica.

7. The composition of claim 2, wherein the resin composition iscovalently bonded to a surface of the silica particulates.

8. The composition of claim 2, further comprising: a matrix in which thesilica particulates are dispersed to form a matrix blend, the matrixcomprising a rubber material or a polymer material.

9. The composition of claim 8, wherein the silica particulates areuniformly dispersed in the matrix blend.

10. A composition comprising: a plurality of particulates comprisingprecipitated silica; and a biologically derived resin compositionpre-coated onto a surface of the plurality of particulates, thebiologically derived resin composition being covalently bonded thereto.

11. The composition of claim 10, wherein the biologically derived resincomposition comprises a rosin-based resin, a terpene-based resin, or anycombination thereof.

12. The composition of claim 11, wherein the biologically derived resincomposition comprises a rosin ester resin, a liquid polyterpene resin,or any combination thereof.

13. The composition of claim 11, further comprising: a matrix in whichthe plurality of particulates is dispersed to form a matrix blend, thematrix comprising a rubber material or a polymer material.

14. The composition of claim 10, further comprising: a matrix in whichthe plurality of particulates is dispersed to form a matrix blend, thematrix comprising a rubber material or a polymer material.

15. A tire comprising the composition of claim 13.

16. A tire comprising the composition of claim 14.

17. A method comprising: providing a plurality of particulates; andpre-coating a resin composition onto a surface of the plurality ofparticulates; wherein the resin composition comprises a rosin-basedresin, a terpene-based resin, a C5-C9 resin, a hydrogenated resin, apolymerization-modified rosin resin, a styrenated terpene resin, apolyterpene resin, a phenolic terpene resin, a resin dispersion, anα-methyl styrene monomer resin, an α-methyl styrene phenolic resin, orany combination thereof.

18. The method of claim 17, wherein the resin composition comprises arosin-based resin, a terpene-based resin, or any combination thereof.

19. The method of claim 18, wherein the resin composition comprises arosin ester resin, a liquid polyterpene resin, or any combinationthereof.

20. The method of claim 17, wherein the plurality of particulatescomprises silica particulates.

21. The method of claim 20, wherein the resin composition is covalentlybonded to a surface of the silica particulates.

22. The method of claim 20, wherein the silica particulates compriseprecipitated silica particulates.

23. The method of claim 20, wherein the resin composition comprises arosin-based resin, a terpene-based resin, or any combination thereof.

24. The method of claim 17, further comprising: after pre-coating,blending the plurality of particulates with a matrix to form a matrixblend, the matrix comprising a rubber material or a polymer material.

25. The method of claim 24, wherein the plurality of particulates isuniformly dispersed in the matrix blend.

26. The method of claim 24, further comprising shaping the matrix blendto form a tire.

27. A method comprising: providing a plurality of particulatescomprising precipitated silica; and pre-coating a biologically derivedresin composition onto a surface of the plurality of particulates, thebiologically derived resin composition being covalently bonded thereto.

28. The method of claim 27, wherein the biologically derived resincomposition comprises a rosin-based resin, a terpene-based resin, or anycombination thereof.

29. The method of claim 28, wherein the biologically derived resincomposition comprises a rosin ester resin, a liquid polyterpene resin,or any combination thereof.

30. The method of claim 28, further comprising after pre-coating,blending the plurality of particulates with a matrix to form a matrixblend, the matrix comprising a rubber material or a polymer material.

31. The method of claim 30, wherein the plurality of particulates isuniformly dispersed in the matrix blend.

32. The method of claim 27, further comprising shaping the matrix blendto form a tire

33. The method of claim 27, further comprising after pre-coating,blending the plurality of particulates with a matrix to form a matrixblend, the matrix comprising a rubber material or a polymer material.

34. The method of claim 33, wherein the plurality of particulates isuniformly dispersed in the matrix blend.

35. The method of claim 33, further comprising shaping the matrix blendto form a tire.

For the purposes of this specification and appended claims, unlessotherwise indicated, all numbers expressing quantities, percentages orproportions, and other numerical values used in the specification andclaims, are to be understood as being modified in all instances by theterm “about.” Accordingly, unless indicated to the contrary, thenumerical parameters set forth in the following specification andattached claims are approximations that can vary depending upon thedesired properties sought to be obtained. It is noted that, as used inthis specification and the appended claims, the singular forms “a,”“an,” and “the,” include plural references unless expressly andunequivocally limited to one referent. As used herein, the term“include” and its grammatical variants are intended to be non-limiting,such that recitation of items in a list is not to the exclusion of otherlike items that can be substituted or added to the listed items. As usedherein, the term “comprising” means including elements or steps that areidentified following that term, but any such elements or steps are notexhaustive, and an embodiment can include other elements or steps.

Unless otherwise specified, the recitation of a genus of elements,materials or other components, from which an individual component ormixture of components can be selected, is intended to include allpossible sub-generic combinations of the listed components and mixturesthereof.

The patentable scope is defined by the claims, and can include otherexamples that occur to those skilled in the art. Such other examples areintended to be within the scope of the claims if they have structuralelements that do not differ from the literal language of the claims, orif they include equivalent structural elements with insubstantialdifferences from the literal languages of the claims. To an extent notinconsistent herewith, all citations referred to herein are herebyincorporated by reference.

1. A resin-covered silica composition comprising: finely divided silica,a first resin selected from the group consisting of a coumarone-indeneresin consisting of coumarone and indene repeat units, a petroleumhydrocarbon resin; consisting of petroleum hydrocarbon repeat units, andoptionally, aliphatic olefin units, phenol units, or cresol units; aterpene-based resin selected from the group consisting of a polyterpeneresin and a terpene phenol resin, wherein the polyterpene resin consistsof terpene repeat units; and the terpene phenol resin consists ofterpene and phenol repeat units; a styrene-alpha-methylstyrene resinsconsisting of styrene and alpha-methylstyrene repeat units, rosinderived resins and copolymers, and mixtures thereof; and wherein theresin-covered silica is formed in a process consisting essentially ofcoating the finely divided silica with a composition consistingessentially of the first resin to coat at least a surface of the finelydivided silica forming the resin-covered silica as separate silicaparticles coated with the first resin, wherein the first resin is notchemically bonded to the finely divided silica, and wherein the separatesilica particles coated with the first resin forming the resin-coveredsilica have an average primary particle size increase of less than 10%compared to the average primary particle size of the finely dividedsilica.
 2. The resin-covered silica composition of claim 1, where theseparate silica particles coated with the first resin forming theresin-covered silica have an average primary particle size increase ofless than 5% as compared to the average primary particle size of thefinely divided silica.
 3. The resin-covered silica composition of claim2, where the separate silica particles coated with the first resinforming the resin-covered silica have an average primary particle sizeincrease of less than 2% compared to the average primary particle sizeof the finely divided silica.
 4. The resin-covered silica composition ofclaim 1, wherein coating the finely divided silica with the compositionconsisting essentially of the first resin comprising: providing adispersion comprising the first resin; mixing the finely divided silicawith the dispersion to form a mixture, wherein at least a surface of thefinely divided silica is coated with the resin; and drying the mixtureto form the resin-covered silica as separate silica particles coatedwith the resin.
 5. The resin-covered silica composition of claim 1,wherein coating the finely divided silica with the compositionconsisting essentially of the first resin comprising: providing adispersion comprising the first resin; and spray coating the finelydivided silica with the dispersion comprising the first resin to coat atleast a surface of the finely divided silica with the first resin. 6.The resin-covered silica composition of claim 1, wherein the finelydivided silica is selected from the groups consisting of untreated,precipitated silica, crystalline silica, colloidal silica, aluminumsilicates, calcium silicates, fumed silica, and mixtures thereof.
 7. Theresin-covered silica composition of claim 1, wherein the finely dividedsilica comprises precipitated silica having a CTAB specific surface arearanging from 60 to 300 m²/g.
 8. The resin-covered silica composition ofclaim 1, wherein the finely divided silica comprises precipitated silicahaving a BET surface area, as measured using nitrogen gas, from 40 to600 m²/g.
 9. The resin-covered silica composition of claim 1, whereinthe finely divided silica has an average primary particle size of <1000μm.
 10. The resin-covered silica composition of claim 1, wherein thefirst resin is a terpene polymer consisting of terpene units selectedfrom the group consisting of α-pinene units, β-pinene units, δ-3 careneunits, limonene units, dipentene units, β-phellandrene units α-pinenepyrolysate units, β-pinene pyrolysate units, δ-3 carene pyrolysateunits, δ-2 carene pyrolysate units, turpentine pyrolysate units,dipentene pyrolysate units, limonene pyrolysate units, and combinationsthereof.
 11. The resin-covered silica composition of claim 1, whereinthe terpene-based resin is selected from the group consisting ofpolyterpene resins and terpene phenol resins.
 12. The resin-coveredsilica composition of claim 1, wherein the first resin is a petroleumhydrocarbon resin.
 13. The resin-covered silica composition of claim 12,wherein the petroleum hydrocarbon resin is selected from the groupconsisting of coumarone-indene resins, indene resins, aromatic vinylpolymers obtained by polymerizing α-methylstyrene and/or styrene, C9hydrocarbon resins, resins derived from cyclopentadiene homopolymer orcopolymer resins, dicyclopentadiene homopolymer or copolymer resins, C5fraction homopolymer or copolymer resins, C9 fraction homopolymer orcopolymer resins, alpha-methylstyrene homopolymer or copolymer resins,and combinations thereof.
 14. The resin-covered silica composition ofclaim 1, wherein the process for forming the resin-covered silicafurther comprises coating the finely divided silica with a second resinafter coating the finely divided silica with the composition consistingessentially of the first resin, wherein the second resin is same ordifferent from the first resin.
 15. A method for preparing aresin-covered silica, comprising the steps: providing finely dividedsilica; providing a first composition consisting essentially of a firstresin; coating the finely divided silica with the first compositionconsisting essentially of the first resin to form a mixture, wherein atleast a surface of the finely divided silica is coated with the firstresin; drying the mixture to form the resin-covered silica; and whereinthe resin-covered silica has an average primary particle size differenceof less than 10% as compared to the average primary particle size of thefinely divided silica; wherein the first resin is not chemically bondedto the finely divided silica, and wherein the first resin is selectedfrom the group consisting of: a coumarone-indene resin consisting ofcoumarone and indene repeat units; a petroleum hydrocarbon resinconsisting of petroleum hydrocarbon repeat units, and optionally,aliphatic olefin units, phenol units, or cresol units; a terpene-basedresin selected from the group consisting of a polyterpene resin and aterpene phenol resin, wherein the polyterpene resin consists of terpenerepeat units; and the terpene phenol resin consists of terpene andphenol repeat units; a styrene-alpha-methylstyrene resins consisting ofstyrene and alpha-methylstyrene repeat units, rosin derived resins andcopolymers, and mixtures thereof.
 16. The method of claim 15, furthercomprises coating the resin-covered silica with a second compositionconsisting essentially of a second resin, wherein the second resin issame or different from the first resin.
 17. The method of claim 16,whether the second resin is different from the first resin.
 18. Themethod of claim 16, wherein the resin-covered silica has an averageprimary particle size difference of less than 5% as compared to theaverage primary particle size of the finely divided silica;
 19. Themethod of claim 16, wherein the first composition consisting essentiallyof the first resin is any of: a dispersion of the first resin in asolvent, a solution of the first resin dissolved in an organic solvent,or the first resin in a liquid form.
 20. The method of claim 16, whereincoating the finely divided silica with the first composition consistingessentially of the first resin comprises any of: spraying thecomposition consisting essentially of the first resin onto the finelydivided silica; and mixing the finely divided silica with thecomposition consisting essentially of the first resin.